﻿using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.DependencyInjection;
using Serilog;

namespace OcelotApiGw
{
    public class Program
    {
        public static readonly string ConfigurationJson = "appsettings.json";
        public static readonly string Namespace = typeof(Program).Namespace;
        public static readonly string AppName = Namespace;
        public static void Main(string[] args)
        {
            var configuration = GetConfiguration();
            Log.Logger = CreateSerilogLogger(configuration);
            try
            {
                Log.Information("Configuring web host ({ApplicationContext})...", AppName);
                var host = BuildWebHost(args);
                Log.Information("Starting web host ({ApplicationContext})...", AppName);
                host.Run();
            }
            catch (Exception ex)
            {
                Log.Fatal(ex, "Program terminated unexpectedly ({ApplicationContext})!", AppName);
            }
            finally
            {
                Log.CloseAndFlush();
            }
            
        }
        public static IWebHost BuildWebHost(string[] args)
        {
            IWebHostBuilder builder = WebHost.CreateDefaultBuilder(args);
            builder.ConfigureServices(s => s.AddSingleton(builder))
                .ConfigureAppConfiguration(ic => ic.AddJsonFile(Path.Combine("configuration", "configuration.json")))
                .UseStartup<Startup>()
                .UseSerilog();
            IWebHost host = builder.Build();
            return host;
        }
        private static Serilog.ILogger CreateSerilogLogger(IConfiguration configuration)
        {
            var seqServerUrl = configuration["Serilog:SeqServerUrl"];
            var logstashUrl = configuration["Serilog:LogstashgUrl"];
            return new LoggerConfiguration()
                .MinimumLevel.Verbose()
                .Enrich.WithProperty("ApplicationContext", AppName)
                .Enrich.FromLogContext()
                .WriteTo.Console()
                .WriteTo.Seq(string.IsNullOrWhiteSpace(seqServerUrl) ? "http://seq" : seqServerUrl)
                .WriteTo.Http(string.IsNullOrWhiteSpace(logstashUrl) ? "http://logstash:8080" : logstashUrl)
                .WriteTo.RollingFile(configuration["Serilog:RollingFile"])
                .ReadFrom.Configuration(configuration)
                .CreateLogger();
        }
        private static IConfiguration GetConfiguration()
        {
            var builder = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile(ConfigurationJson, optional: false, reloadOnChange: true)
            .AddEnvironmentVariables();
            var config = builder.Build();
            if (config.GetValue<bool>("UseVault", false))
            {
                builder.AddAzureKeyVault(
                    $"https://{config["Vault:Name"]}.vault.azure.net/",
                    config["Vault:ClientId"],
                    config["Vault:ClientSecret"]);
            }
            return builder.Build();
        }
    }
}
